Category: Linux

  • wget

    Mirroring a site with wget
    wget print content to screen
    wget force IPv4/6 download

    Download Multiple Files

    To download multiple files from FTP server, run

    wget ftp://backup2.serverok.in/backup1/*.tar.gz --ftp-user=USER --ftp-password=PASSWORD

    Download all files in a folder

    wget -r -l1 --no-parent http://cloud.serverok.in/public/

    Download Entire Website

    wget \
 --recursive \
 --no-clobber \
 --page-requisites \
 --html-extension \
 --convert-links \
 --restrict-file-names=windows \
 --domains example.com \
 --no-parent \
     www.example.com

    Or

    wget --mirror --convert-links --adjust-extension --page-requisites --no-parent https://domain.com/

    Download with Limit Rate

    wget -c --limit-rate=60k http://dn.serverok.in/1.mkv

    This limits the download rate to 60.0KB/s

    Back to Linux Commands

  • Mirroring a site with wget

    To mirror a web site for local viewing, you can use

    wget --mirror --convert-links --html-extension --wait=2 -o log http://www.domain.com

    –convert-links = After downloading, convert the links suitable for local viewing.

  • Atlassian JIRA Internal Server Error

    On on Jira Server, when accessing the site get following error

    JIRA — Internal Server Error
    Error reference: b64e4876-0fc1-439a-a46d-4a3255a48230

    Unable to render full error details at this time. Please consult the error logs for more information.

    The problem was disk full.

    root@jira /var/atlassian/application-data/jira # du -h –max-depth=1
    1.1M ./analytics-logs
    4.0G ./plugins
    293M ./log
    72K ./structure
    32M ./tmp
    11M ./caches
    632K ./logs
    52K ./tempo
    32G ./export
    368M ./data
    96K ./import
    352K ./monitor
    4.0K ./logos
    8.5M ./bt-templates
    37G .
    root@jira /var/atlassian/application-data/jira #

    The folder /var/atlassian/application-data/jira/export used 32 GB disk space. This folder store daily backups.

    I removed some of the older backups last last year, restarted the server, that fixed the problem.

    To avoid this happening again, set a cronjob

    vi /usr/serverok/clean.sh

    Add

    #!/bin/bash

/bin/find /var/atlassian/application-data/jira/export/ -type f -mtime +60 -name "*.zip" -delete

    This will delete files older than 60 days.

    Set it to run daily with crontab -e

    @daily  /usr/serverok/clean.sh > /dev/null 2>&1

  • Enable Error Logging in php-fpm

    Edit your pool file

    vi /etc/php/7.0/fpm/pool.d/www.conf

    Add

    catch_workers_output = yes
php_flag[display_errors] = on
php_admin_value[error_log] = /var/log/fpm-php.www.log
php_admin_flag[log_errors] = on

    if you only enable “log_errors”, then errors go to default nginx error log.

    php-fpm

  • mount

    Remount a file system in rw mode

    mount -o remount,rw /

  • Mount Windows Share in Linux

    On Ubuntu, install cifs-utils

    apt-get install cifs-utils

    First create a directory on which we can mount the windows share

    mkdir /media/SHARE_NAME

    Now create a file to store windows share username and password.

    vi /etc/SHARE_NAME.smbcredentials

    Add following to the file

    username=YOUR_WINDOWS_SHARE_USER
password=YOUR_WINDOWS_SHARE_PASSWORD

    Now run

    mount -t cifs //192.168.0.4/SHARE_NAME /media/SHARE_NAME -o credentials=/etc/SHARE_NAME.smbcredentials,uid=LINUX_USER_NAME,iocharset=utf8,sec=ntlm,rw,dir_mode=0777,file_mode=0666

    192.168.0.4 – Replace with IP of your Windows computer with share.

    LINUX_USER_NAME – Replace with the Linux user name you want the files to be owned.

    To make share mounted on boot, edit 

    vi /etc/fstab

    Add

    //192.168.0.4/SHARE_NAME  /media/SHARE_NAME  cifs  credentials=/etc/SHARE_NAME.smbcredentials,uid=LINUX_USER_NAME,gid=GID_OF_LINUX_USER,_netdev,iocharset=utf8,dir_mode=0777,file_mode=0666  0  0

    mount

  • Debian 9 OVH Bridge Network Configuration

    When you run VPS on OVH network behind bridge network, you need to create VMAC for each IP and assign to your network card.

    Once this is done, you need to use following network configuration in your /etc/network/inferfaces file.

    auto lo ens18
iface lo inet loopback
auto ens18
iface ens18 inet static
    address FAILOVER_IP
    netmask 255.255.255.255
    broadcast FAILOVER_IP
    post-up ip route add GATEWAY_IP dev ens18
    post-up ip route add default via GATEWAY_IP dev ens18
    pre-down ip route del GATEWAY_IP dev ens18
    pre-down ip route del default via GATEWAY_IP dev ens18

    FAILOVER_IP = the IP you will be using for the virual machine.

    GATEWAY_IP = IP of the Host server with last digits replaced by 254. If your servers main IP is XX.YY.ZZ.100, then Your GATEWAY_IP is XX.YY.ZZ.254

    Here is an example config file i use in one of my VPS

    auto ens18
iface ens18 inet static
    address 198.50.234.186
    netmask 255.255.255.255
    broadcast 198.50.234.186
    dns-nameservers 8.8.8.8 8.8.4.4
    post-up ip route add 158.69.124.254 dev ens18
    post-up ip route add default via 158.69.124.254 dev ens18
    pre-down ip route delete 158.69.124.254 dev ens18
    pre-down ip route delete default via 158.69.124.254 dev ens18

    I made a pull request to OVH as OVH documentation use route command, that is deprecated in Debian 9 and Ubuntu 18.04. We need to use “ip route” command instead of “route” command.

  • Resize gcow2 image with qemu

    To resize gcow2 image, run

    qemu-img resize FILE.qcow2 +10GB

    To create a gcow2 image, run

    qemu-img create -f qcow2 -o preallocation=metadata FILE.new 10G

    You can also use

    virt-resize --debug  --expand /dev/vda1 FILE.qcow2 FILE.qcow2.new

    virt-resize is part of http://libguestfs.org

  • 500 I won’t open a connection to x.x.x.x (only to y.y.y.y)

    500 I won’t open a connection to x.x.x.x (only to y.y.y.y)

    When connecting to FTP server from a remote server hosted in Microsoft Azure i get error

    500 I won’t open a connection to x.x.x.x (only to y.y.y.y)

    This is because you are behind NAT firewall and trying to use FTP in Active mode.

    To fix the error, enable FTP passive mode with command

    passive

    ftp

  • Linux Tar Command: Create, Extract, and Compress Archives

    Tar is a widely used Linux archiving tool—short for “tape archive” that bundles multiple files and directories into a single archive (a tarball) while preserving paths, permissions, ownership, and timestamps, and it can also compress or extract those archives for efficient backup, distribution, and recovery.

    To create a compressed tar (tar.gz or tgz) file, run

    tar -czvf backup.tgz FOLDER

    Replace FOLDER with name of the directory you need to compress. It will create a backup.tgz file with all content of the specified directory.

    To extract a tar/tar.gz/tgz file, run

    tar xvf file.tar.gz

    Uncompress tar.bz2 file

    tar -jxvf ncftp-3.2.2-src.tar.bz2

    Create a tar file

    tar -cvf file.tar FOLDER_NAME

    Example

    tar -cvf backup.tar public_html

    Once backup.tar file is created, you can make it tar.gz with command

    gzip backup.tar

    Exclude a folder from tar file

    To exclude a folder, you can use –exclude option. 

    tar cvf backup.tar --exclude=public_html/uploads --exclude=public_html/wordpress public_html

    List content of a tar file

    tar --list --verbose --file=BACKUP.tar.gz

    If you want to exclude a folder from the file list, use

    tar --list --verbose --file=BACKUP.tar.gz --exclude=home/haridy/Maildir

    This will exclude all files that are inside folder “home/haridy/Maildir”. You can use multiple –exclude if required.

    Using tar over SSH Session
    Split Large file into smaller files
    How to view the contents of tar.gz file

  • Debian

    Debian is a powerful, stable, and versatile open-source operating system used by millions of servers and desktops worldwide. Known for its reliability, security features, and large repository of free software packages, Debian serves as the foundation for many popular Linux distributions.

    Debian is the core foundation for many popular Linux distributions, with Ubuntu being the most widespread derivative. Ubuntu builds on Debian’s stability but focuses on ease of use, frequent updates, and broader hardware support, making it ideal for beginners and enterprises.

    Debian Upgrade

  • Unable to detect ICU prefix

    When compiling PHP, i get following error.

    checking whether to enable internationalization support… yes
    checking for icu-config… no
    checking for location of ICU headers and libraries… not found
    configure: error: Unable to detect ICU prefix or no failed. Please verify ICU install prefix and make sure icu-config works.

    To fix, install libicu dev package.

    On CentOS/RHEL

    yum -y install libicu-devel

    On Debian/Ubuntu

    apt -y install libicu-dev

    Errors